Apparatus for pouring melted metal under pressure



l June 6, 1933- R. v. cHRlsTENsEN yErr AL 1,913,071

APPARATUS FOR POURING MELTED METAL UNDER PRESSURE Filed Jan. 2, 1951 2Sheets-Sheet 1 Inventors i@ M M M 5f Ama/L4 ,0M/La, /lforneys June 6,1933. R. H. v. cHRlsTl-:NSEN Er AL 1,913,071

APPARATUS FOR POURING MELTED METAL UNDER PRESSURE Filed Jan. 2, 1931 2Sheets-Sheet 2 3 Z2- 7 W (y.

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Y AMM 4 zum 4% M4 Patented .lune 6, 1933 UNITED STATES PATENT ori-lcsBEINHABDT HARALD A PPABA'TUS FOB POUBING HELTED METAL UNDER PRESSUREApplication lled- January 2, 1931, Serial No.

`This invention aims to provide an improved process and apparatus forpourlng molten metal, such as iron, phosphor-bronze and aluminium underpressure.

In castings of this nature it is known to withdraw the molten metal fromthe crucible by means of a pourin ladle, which is then connected to themoul The process according to the present invention is distingulshedfrom -this in that the metal isA transferred from the ladle to the mouldbythe creation in the mould of a relatively low differential pressure,for instance a vacuum, that the inlet of the mould is then closed, andthat the metal enclosed in the mould is then exposed to a pressure.According to the 1nvention the vacuum in the mould may be produced bythe air in the mould being sucked out at several points.

The apparatus according to the invention is partly characterized in thata portion of the inlet of the mould is formed by a cylindrical channeladapted to receive a piston, which piston, when moved forward towardsthe mould cavity, first closes the connection to the latter and thenexerts a pressure on the. enclosed metal. Other distinguishing featuresof the apparatus will appear from the foilowing description of variouspracticable embodiments of the invention as shown in the drawings,wherein Fig. 1 lillustrates a casting machine, in side elevation, partlyin section,

ig. 2 is a top view of the same, ig. 3 illustrates anotherconstructional form of casting machine in side elevation,

partly in section; and

Fig. 4 is across-section of the latter on the line IV``IV of Fig. 3,showing associated valve mechanism employed vin both constructions.

The casting machine shown in Figs. 1 and 2 embodies a frame 10 fitted atthe ends with brackets` 11 interconnected by round bars 12 serving asguide bars. Two holding `plates 13 and a holding member 14 are adaptedto slide on these bars, and the member 14 is adjustably connectedto oneof the holding plates 13 y means of threaded sleeves 15 provided on thebars 12. The parts 16 506,280, and in Denmark January 7, 1980.

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of the mould areconnected to or between the holding plates 13 in suchpositions that the mould parts will engage one another correctly, whenthe holding plates are drawn toward one another. In one of the brackets11 a shaft 17 is journaled, which shaft supports two toothed segments 18engaged by pinions 19, which are mounted on another shaft 20 journaledin the same bracket and actuated at one end b a capstan wheel 21. Arms22, integral wit the segments 18, together with length-adjustable linkmembers 23 form knee-presses adapted to actuate the holding member 14when the capstan 21 is rotated.

At one end of the casting machine a vfurnace 24 is provided, containlnga crucible 25, in which the casting material is heated.

The transfer of the molten metal to the mould 16 is effected by apouring ladle 26 which in the present instance is made of a vrefractorymaterial shaped like a block and having a mainly U-shaped channel 27adapted to hold the mould charge. This ladle is suspended with freepivoting on a crank 27', the shaft 28 of which is journaled in a bracket29 attached to one of the brackets 11 and adapted to be actuated bymeans of a crank handle 30. For transferring the ladle from the crucibleto the mould,v the shaft 28 is turned through an angle of 270 b thehandle 30, whereafter the ladle will in the position shown in Fig. 1. Inthis position, one orifice of the channel 27 communicates with the inlet31 of the mould by way of a refractory lining 32 inserted in one of theholding plates 13. The other orifice of the channel 27 communicates withthe at-` mosphere by lway of a sleeve 33 forming a resilient support forthe ladle 26, as the sleeve 33 is adapted to slide in the abovementioned bracket 11, counteracted by a spring 34. When the pouringladle is situated in theI above mentioned osition, then the mould parts16 are moved) together by means of the aforedescribed knee-presses 22,23 actuated b the capstan 21. When the mould parts ave come into contactwith one another, they are moved to ether a short distance by furtherrotation o the capstan,

. determined by the tension of the sprin 'until the front holding plate13 strikesa suitable stop. During this last motion the` ladle 26 ispressed firmly between the lining 32 and the sleeve 33 under a pressizieB thismeans it is assured that the la e 26 will not be subjected toexcessive lateral pressures or stresses. .The liquidmetal taken up inthe channel 27 of the ladle is drawn. in to the cavity 35 of the mould ba vacuum created in the latter. From t e mould cavity a .channel 36extends, whichl at the start is situated in the dividing surface betweenthe `mould parts, i. e. half of the channel is worked into -each mouldpart, and then `the channel is continued in the foremost mould part 16(situated next to the furnace 24) From the channel 36 extends a flexiblepipe` 37, which by way of a valve 38 leads to av suction pump (not-showng If desir the liquid metal may also be transferred to the mould bysupplying compressed air, at a relatively low pressure to the sleeve 33on the other side of theladle A portion of the inlet of the mould isformed by a cylindrical channel 38 adapted to receive a rod-like plunger39 which latter when moved forward towards the mould cavity 35, firstcuts off thev connection from p the pouring ladle 26 to said cavity, andthen exerts a pressure on the enclsed metal. The axis of the plunger 39is mainl situated in the dividing plane of the moul in 'such amannerthat the solidified plug of metal below the lunger can be removedtogether with the ead head inthe inlet, when the mould parts areseparated at the removal of the casting. t i

'The' plunger 39 supports at lts extreme end a disc 40 forming thepiston for a cylinder 41, to the top part of which compressed air can besupplied by way of a 'valve 42 and a pipe 43 from a not shown source ofcompressed air, when said piston is to Alie-moved inward. The cylinder41 is sup rted by a bracket 44 attached to the front olding plate 13, sothat the cylinder is always in firm connection with the fore? most mouldpart 16. The piston 39' will therefore continue to be inl contact withthis mould part, when the other mould part is withdrawn duringremoval'of the casting. To the rear holding plate 13 there is attachedan arm 45, the extreme bent end of which co-operates with a stop "46 onthe plunger 39, whenthe said holding plate is moved back, so that theplunger 1s` automatically returned to the initial positionv l'when themould is opened.-

The valves 38 and 42 are conveniently mounted in a bracket affixed tothe front holding plate or frame, with the first-named -'(38) thereofcontrolling a connection of the pipe 37 with a pipe 72 leadin ,to theaforetageously-controlled by a common device which in the illustrativeexample is forme by a two-armed lever 47, which is pivoted on a pin 48and one arm of which co-o erates with the spindles of the valves, whi ethe other arm is adapted tobe actuated from v the rear end of thecasting machine by a cord or chain 49. By this arrangement the advantageis attained that the two valves are always o rated jinproper succession,the valve 38be1ng opened first and then the valve 42.

It should be noted thatl the first art of the exhaust channel 36 is sonarrow t at the melted metal vwill 'solidify from` cooling against theform parts l16 before assing any appreciable distance into this c annel,which will therefore become clogged. Accordingly, the melted metalcannot possibly be suckedv out through the pipe 37.

The modification or construction of the casting machine shown in Figs. 3and'4 will now be described in so far as it differs from that justdescribed.

the rear holding plate 13 and the mold part .16 supported y the same,l a'su orting member 51, whereby space isprovi ed for a not shown mechanismserving to withdraw any cores used in connection with the mould. Thefront holding plate 13 is stationary, and is constructed as a bracketattached directly to the frame 10. f

The-melted metal is supplied to the mould by way of 4an angular inletpipe 52 made preferably from refractory material. This pipe is placed insuch manner that one branch thereof is vertical and the other onehorizontal. The horizontal branch passes air-tight through the frontholding plate 13, against which the corresponding mould part 16 ispressed air-tightly, and lends ata cavity 53 in the mould, from whichcavity the inlet proper 54to the cavity 35 of the mould extends. Theoutlet orifice from the horizontal branch opens to the inlet 54. The

inlet orifice at the free end of the vertical avslit. 57 or thehorizontal branch of the inlet pipe and, along a' horizontal plane someIn this machine there is inserted, between i 4u of the miaou distanceabovev the bottom, lone or more openings 58 determining the to level ofthe quantity of metal contained 1n the pipe.

The pi 56 is suspended on a mechanical A `l moving evice actuatedautomatically by the of the movablemould part towardsthe stationar mouldpart the pipe'56 will be raised to suoli a level that just one mouldcharge will be taken up to be transferred from this pipe to the inletpipe 52 by suction through the last mentioned pipe. The distance betweenthe liquid level in the raised pipe v56 and the downward. facing orificeof the pi 52 is in fact the feature determining t e quantity of metal tobe transferred to the mould, because when the liquid level reaches thesaid orificel the intake of metal will cease, l whereafter only thecolumn of metal con tained in the pipe 52 will be conveyed to the mouldowing toits kinetic energy.

`In this modified construction as shown 1n Fig. 4, the piston 39 and thecylinder 41 are 35 disposed in sloping manner, in order to provide spacefor the end of the pipe 52 situated in the cavity 53. V

TheV channel by way of which the mould is evacuated is in this caseramified and con- 0 nected to the mould vcavity 35 at several points.Hereby any accumulation of' air in v the mould during the pouring willbe avoided, and the effect of any leaks will be eliminated. Theramification is effected by cut- 5 ting furrows or grooves 63 in thecontacting surfaces of the `mould parts, which grooves when the mouldparts are placed together form a channel, which encircles all thecavities 'of ythe mould, and from Where branches 64 extend to the saidcavities. The annular channel is connected to the suction line 37' byWay of the channel 36 in the front stationary mould part 16.

The machine isotherwise constructed in 55 similar manner to that firstdescribed, and the corres onding parts in the two machines are mar edwith the same reference numerals.

In this construction of the machine the 6 liquid metal transferred byway of the pipe 52 will first be received by the cavity 53, which issufficiently large to hold the entire mould charge. From this cavity themetal is conve ed to the mould cavity, mainly by 05 action o gravityalone.

art. The screw 62 can be adfv 'The here describedconstructions may bemodified 1n various respects without deviation from the essentialfeatures of the inention. `Thus the iston which `limits the mould chargerecelved by the mould and exerts a pressure thereon may be moved bypurely mechanical means, such as a screw or the like, instead of thevalve mechanism shown and described in detail with reference to Figs. 1and 2. y i

vThe advantage of the process accordin to the present invention is notonly that allbys and metals with high melting point and being difficult.to pour can be cast, but lalso denser and more uniform .castings areattained than according to the here known squirting method of casting,accord- 1ng to which a metal superheated above the fusmg point is flungforcefully into the moul By this last mentioned casting method theintroduction of the metal is so `violent thatv it is flung against thewalls of the mould in such a' manner that at certain points the air inthe mould may become enclosed, while the metal, where the wall' is thin,may become solidified before the entire pouring is finished, theconsequence be- .ing that the advantages of the pressure used cannotmanifest thelnselves. The castings will therefore be porous and lessuniform. and may contam air blisters. These drawbacks may certainly beavoided by another.

known casting method, i. e., the so-called chill casting, which method,however, is not suited for mass-production and does not give so fine andsharp castings as does lthe squirting method. A' distinguishing featureof th rocess according to the present method is tfi at the metal isintroduced into the mould by a rela? tively loW differential pressure,so that the conditions will be approximately the same as if the metalwere poured' into4 the mould, and that the metal is then exposed to aconsiderable pressure, so that it will fill the mould entirely. The useof a high pressure on the metal, after the same is introduced into themould, is mainl rendered practicable by the feature that t e pressuredoes not act on the ladle.

Having now particularly described and ascertained the nature of ourinvention and in what manner the same is to be performed `We declarethat what We claim is:

1. In an apparatus for casting metal under pressure, a mould, a ladleadapted to receive molten metal and to be subsequently connected withthe mould, an inlet channel in the body of the mould arranged tocolnmunicate with the ladle when the latter is connected with the mouldand situated above the mould cavity so as to allow the molten metal tobe transferred against the action of gravity from the ladle to saidinlet channel and to fill the mould cavity by gravity,

a second'channel situated in the body o f the mould and communicatingwith said inlet channel, and a plunger arranged to advance in saidchannel so as to cut of the flow of 5 the molten metal from the ladle tothe inlet channel and to subsequently subject the metal in the mould topressure.

2. An apparatus for castin metal under pressure, comprisin a mou dformed, in

10 two parts, an inlet c annel for molten metal disposed in the body ofthe mould above the mould cavity, a ladle adapted to receive moltenmetal and to be connected with the mould so as to communicate with saidinlet channel of the latter by an upwardly disposed passage throughwhich the metal may be transferred from the one to the other againstgravity action, a channel formed by the two parts of the mould andcommunicating with said inlet channel, and a plunger arranged to advancein the lastnamed channel so as to cut olf the flow of the molten metalfrom the ladle to the mould and to thereafter subject the metal in themould to pressure.

3. An apparatus for casting molten metal under pressure, comprising amould formed in two parts, an inlet channel. in one part of the mouldabove the mould cavity, a channel formed by the two parts of the mouldin communication with said inlet channel, a ladle adapted to receivemolten "metal and to be connected with the mould, communicating passageswith -means for forcing the molten metal from the ladle into said inletchannel against gravity action and to allow the molten metal thereafterto fill the mould cavity by gravity, a plun er located in thesecond-named channe and means for advancing the plunger in saidsecond-named channel so as to first cut off the molten metal suppl fromthe ladle to the mould and then subject the molten metal within themould to pressure.

4.l An apparatus for castin molten metal under pressure, comprising amould formed in two parts, an inlet channel in one of said parts at alevel higher than the mould cavity, another channel formed lin the twoparts of the mould and communicating with said inlet channel, a ladleadapted to receive molten metal and to be connected with the mould in anupward passage communication with said inlet channel thereof, anevacuating channel in the mould body communicating with said mouldcavity and therethrough with said inlet channel, means for creating avacuum in the mould through the evacuating channel to draw the moltenmetal. from the ladle into the inlet channel of the mould a inst gravityaction and allowing the meta to flow from said inlet channel into themould by gravity, means for interrupting the vacuum action, a plungerworking in the 5 second-named channel, and means for mov- Vof moltenmetal from the ladle to the inlet channel and then to subject themoltenpmetal fed into the mould cavity to pressure.

5. An apparatus for casting molten metal under pressure, comprising amould formed in two parts, an inlet channel in one .of said arts at alevel higher than the mould cavity, a cylindrical channel formed by thetwo parts of the mould and communicating with said inlet, a ladleadapted to receive molten metal and to beconnected with the inlet of themould through an upwardly directed passage, an evacuating channel in themould body -coinmunicating with the mould cavity, meansv for creating asuction through said evacuating channel to draw the molten metal againstgravity action from the ladle into the inlet channel of the mould andallowing the metal to flow from said channel into the mould by gravity,a plunger working in the cylindrical channel, means for interrupting thesuction action and means for moving said plunger to first cut off theiow of metal from the ladle to the inlet channel and then to subjectthemolten metal in and flowing to the mould cavity from the inletchannel by gravity to pressure.

6. An apparatus for casting molten met-v al under pressure, comprising amould formed in two parts, an inlet channel in the body of the mouldabove the mould cavity, an angular inlet pipe projecting into said inletchannel through an airtight seal, a ladle encircling the lower end of adownwardly directed portion of said inlet pipe and arranged to receivepredetermined amounts of molten metal, means for adjusting the ladlevertically to cause the molten metal therein to surround the lower endof said pipe (portion, an evacuating channel in the moul bodycommunicating with the cavity of the mould, means for creating a suctionin the mould through said evacuating channel to draw the metal throughsaid inlet pipe from the ladle to the inlet channel of the mould, acylindrical channel formed by the two parts of the mould incommunication with the inlet channel, a plunger working in saidlcylindrical channel, means for interruptin the suction action in themould when su cient molten metal has been drawn thereinto, and means forthereafter circling the lower end of a downwardl dilrected portionofsald inlet pife an ar- 1 to receive predl'atermine quantities `ofmolten metal, means for adjusting the -l F ladle verticali to bring themolten metal therein aroun the lower end of said pre l rtion, anevacuating channel in the mo d y in cmmun'ication with the mould cavity,means for creating a suction -in the 1 0 mould through said evacuatingchannel to draw the metal from the ladle through the inlet pi to theinlet channel ofthe mould, a cylm rical channel formed by the two partsof the mould in communication with the inlet channel, a plunger workingin said c lindrical channel, means for interruptin t e suction action 1nthe mould when allE cient of the moltenmetal has been drawn thereintoand means 'for thereafter causin the aforesaid plunger in the cylindricat channel to advance to first close the connec tion between the angulartube and the mould cavity and to then subject the metal in the latter topressure. 8. An apparatus for castin metal under pressure, comgrising amould ormed in two parts of whic one is stationa means for moving theother part to andv rom the stationary part, a `ladle adapted to receive9 molten metal and movable automatically in cogeration with theaforesaid means to a etermined raised position when the mould parts arebrought together,I an inletA channel in the mould, an an ular pipehaving one branch fitted airti t in the inlet channel of the mould and te other branch extended downwardly into the lower` end of K the ladle,an evacuatin channel in the mould body communicating with the cav- 4 ityof the mould, means for Aerecting a suction in the mould through saidevacuating channel to draw the metal from the ladle through the angularpipe to the inlet channel of the mould, a cylindrical channel formed bythe two parts of the mould in communication with the inlet channel,` adplunger working in said cylindrical channel, means for interrupting thesuction in the mould when suihcient molten metal has been drawnthereinto, and means for thereafter causing said plunger to advance inits cylin.- ldrical channel tocut oli' the molten metal dow from theladle to the mould cavity and I to then subject the metal in the mouldto pressure. A

REINHARDT HARALD VALDEIAR CIIRISTERSEN. RICHARD Sllfll-l DAHL. v

